Science M.C.Q-[Che-1M]

3. Zinc is more reactive than tin.

1. Calcium.

Explanation:

Calcium reacts with oxygen to form calcium oxide with a high melting point. This compound is also soluble in water.

3. Applying coating of zinc.

4. AgNO₃ solution and copper metal.

4. Blue and colourless respectively.

Explanation:

The solution of Copper sulphate is Blue in color and that of Zinc sulphate is colorless because zinc is more reactive than copper and displaces copper from copper sulphate solution.

4. All the three.

Explanation:

Aluminium is highly reactive as compared to Copper, Iron and Zinc. Therefore Aluminium will displace all the metals from its salt. Thus aluminum will appear in all the three solution.

1. Aluminium is more reactive than zinc.

2. Vigorously with effervescence.

Explanation:

When acetic acid reacts with sodium hydrogen carbonates then brisk effervescence are observed. These effervescence are evolved due to the release of carbon dioxide from sodium hydrogen carbonate.

4. Dark blue and pale green respectively.

4. Greenish and colourless.

4. Prepare e solution of copper sulphate and hang strip of zinc into it.

1. Iron.

Explanation:

Calcium Oxide is formed when Calcium reacts with Oxygen.

But In certain cases, Silicon Dioxide may also be possible (Because its solubility depends on its crystalline structure).

3. Purification of metal

3. An amphoteric oxide.

Explanation:

Zinc oxide can react with both acids and bases to form salt and water.

1. Roasting.

Explanation:

Zinc blende (zinc sulphide or ZnS) is a sulphide ore of zinc. Sulphide ores are converted to metal oxides by roasting (heating in the presence of air). When zinc blende is heated in the presence of surplus air, it is converted into zinc oxide.

3. Gold.

Explanation:

Because gold is less reactive than silver. The other metals are more reactive than silver and can displace it from silver nitrate solution.

1. Sonorousness

2. Electrical conductivity in solid state.

Explanation:

Because ionic compounds conduct electricity only in molten state or when dissolved in water to form aqueous solution.

2. Electrical conductivity in solid state.

Explanation:

Ions which can move are responsible for conduction of electricity. In solid state ions present in ionic compounds are not free to move, thus ionic compounds do not show electrical conductivity in solid state whereas ionic compounds show electrical conductivity in molten states.

4. Fe.

Explanation: Na, Ca and Mg are reactive metals and quickly react with water. At room temperature, the reaction of Fe is very slow but red hot iron reacts with steam to form Fe₃O₄ with hydrogen gas.

3Fe + 4H₂O → Fe₃O₄ + 4H₂​​​​​​​

2. Ag

Explanation: Least reactive metal can be displaced from its solution by other three metals. Silver is least reactive out of given four metals.

2. Ag

Explanation:

Ag will be replaced from the solution of its salt by the other three metals.

3. CO₂

3. Fe₂O₃ + Al.

Explanation:

In this thermite reaction, iron (III) oxide and aluminium powder are combined and heated. Iron oxide gets reduced to iron by the action of reducing agent aluminium and produces excess heat. The molten iron produced is poured in the middle of the broken pieces of irons that are fixed mutually.

3. Dullness.

Explanation: Metals have shining lustre and they mostly do not show any dullness.

3. Copper and HCl(g)

Explanation:

As per the reactivity series, Copper falls below Hydrogen which means its reactivity is lower than that of hydrogen, so it cannot displace hydrogen from hydrochloric acid.

4. CuSO₄ + Fe.

Explanation:

Iron (Fe) is a more reactive metal than copper, which can displace copper from copper sulphate.

4. Au and Ag.

Explanation:

Gold (Au) and silver (Ag) are highly non-reactive. Hence, they are available in native state in nature and do not react with oxygen or any other element in the atmosphere.

3. Fe₃O₄

2. Bromine.

Explanation:

Metals are generally solid while non-metals are solid, liquid and gas. Bromine is a non-metal and exists as liquid.

4. Iodine

1. Graphite

3. Bromine.

Explanation:

Bromine is the non-metal that is a liquid.

1. Mg

Explanation:

Magnesium (Mg) reacts with very dilute HNO_3​ to evolve H_2​ gas.

Mg + 2HNO₃ ​→ Mg(NO_3​)₂ ​+ H₂​

4. Iron.

Explanation:

Iron can be obtained from hematite ore. Hematite ore contains the compound iron (III) oxide (Fe₂O₃).

3. Na and Mg.

Explanation:

Sodium (Na) and magnesium (Mg) are highly reactive metals. They are not easily reduced by carbon and aluminium. Thus, they are extracted by electrolytic reduction or electrolysis of their molten chlorides (sodium chloride, NaCl, and magnesium chloride, MgCl₂).

2. Silver

Explanation:

Silver occurs in native forms since it is very less reactive metals.

4. Hg

Explanation:

Mercury (Hg) is the metal that exists in liquid state at room temperature.

4. Sodium > Magnesium > Zinc > Iron

3. They are ductile.

Explnation:

Non - metals are neither ductile nor malleable.

They are a bad conductor of heat and electricity.

Also, they are non-sonorous and are brittle

2. Cinnabar.

Explanation:

Cinnabar is an important ore of mercury. Its compound is mercury (II) sulphide (HgS).

3. Haematite.

Explanation:

Haematite is an iron ore and the compound is iron (III) oxide (Fe₂O₃).

3. Ethyne.

Explanation:

An ethyne molecule (H - C ≡ C - H) contains a triple bond between two carbon atoms and two single bonds between carbon and hydrogen atoms.

4. CuSO₄ + Fe.

Explanation: Iron is more reactive than copper. Hence, iron displaces copper from copper sulphate solution.

4. Zinc amalgam.

Explanation:

Generally, alloys containing mercury as one of its constituents are known as amalgam. Zinc amalgam is an alloy of zinc and liquid mercury.

3. Steel.

Explanation:

Steel is an alloy that contains a non-metal carbon as one of its constituents. It consists of iron with carbon (0.1 to 1.5%).

1. Sodium

Explanation:

Metals such as potassium and sodium react so vigorously that they catch fire if kept in the open.

Hence, to protect them and to prevent accidental fires, they are kept immersed in kerosene oil.